Sentence examples for upper classes from inspiring English sources

"upper classes" is correct and commonly used in written English.
It refers to the social group or members of society who are considered to have a higher social standing, often based on wealth, education, and/or social status. Example: The upper classes often have access to exclusive opportunities and privileges that are not available to the working class. In this sentence, "upper classes" is used to contrast with the working class and highlight the disparities between the two social groups.